树形结构构造示例代码

/**
 * 构造树形结构
 * @param resourceList
 * @return
 */
public List<RResource> buildResourceTreeInfo(List<RResource> resourceList) {
    List<RResource> result = new ArrayList<>();
    Map<String,RResource> record = new HashMap<>();
    for (RResource resource : resourceList) {
        if (RResource.TOP_LEVEL_NODE.equals(resource.getParentId())) {//TOP_LEVEL_NODE=0
            resource.setChildren(new ArrayList<>());
            result.add(resource);
        }
        record.put(resource.getId(), resource);
    }
    for (RResource resource : resourceList) {
        if (StringUtils.isNotBlank(resource.getParentId()) &&!RResource.TOP_LEVEL_NODE.equals(resource.getParentId())) {//TOP_LEVEL_NODE=0
            RResource parent = record.get(resource.getParentId());
            if (parent != null) {
                parent.getChildren().add(resource);
            }
        }
    }
    return result;
}